---
layout: default
title : "Examples module"
date : "2022-18-06"
author: "the agda-algebras development team"
---
### Examples
This is the [Examples][] module of the [Agda Universal Algebra Library][].
This is the aggregator for the example tree. The submodules group the examples by
flavour, as follows:
+ [Examples.Classical][] collects the worked instances of the classical
structures: canonical first examples, finite groups from Cayley tables, the
small lattices, and deliberate failure modes such as a magma that is not a
semigroup.
+ [Examples.Demos][] collects self-contained demonstrations, among them the
frozen literate artifact of the TYPES 2021 paper.
+ [Examples.FunctionTypeBijections][] and [Examples.PolynomialFunctors][] are
illustrative studies relocated out of the Legacy tree: n-ary function encodings
and their η-obstructions, and polynomial functors with W-types.
+ [Examples.Setoid][] exercises the generic `Setoid/` machinery directly: free
algebras, presentations, quotients, and Birkhoff's HSP theorem specialized to a
concrete algebra.
+ [Examples.Structures][] instantiates the general operations-and-relations
structures of the frozen Legacy tree.
```agda
{-# OPTIONS --without-K --exact-split --safe #-}
module Examples where
open import Examples.Classical
open import Examples.Demos
open import Examples.FunctionTypeBijections
open import Examples.PolynomialFunctors
open import Examples.Setoid
open import Examples.Structures
```